//
// Copyright 2019 Karol Herbst
//
// Permission is hereby granted, free of charge, to any person obtaining a
// copy of this software and associated documentation files (the "Software"),
// to deal in the Software without restriction, including without limitation
// the rights to use, copy, modify, merge, publish, distribute, sublicense,
// and/or sell copies of the Software, and to permit persons to whom the
// Software is furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
// THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
// OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
// ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
// OTHER DEALINGS IN THE SOFTWARE.
//

#include "invocation.hpp"

#include <tuple>

#include "core/device.hpp"
#include "core/error.hpp"
#include "core/module.hpp"
#include "pipe/p_state.h"
#include "util/algorithm.hpp"
#include "util/functional.hpp"

#include <compiler/glsl_types.h>
#include <compiler/nir/nir_builder.h>
#include <compiler/nir/nir_serialize.h>
#include <compiler/spirv/nir_spirv.h>
#include <util/u_math.h>

extern "C" {
#include "nir_lower_libclc.h"
}

using namespace clover;

#ifdef HAVE_CLOVER_SPIRV

// Refs and unrefs the glsl_type_singleton.
static class glsl_type_ref {
public:
   glsl_type_ref() {
      glsl_type_singleton_init_or_ref();
   }

   ~glsl_type_ref() {
      glsl_type_singleton_decref();
   }
} glsl_type_ref;

static const nir_shader_compiler_options *
dev_get_nir_compiler_options(const device &dev)
{
   const void *co = dev.get_compiler_options(PIPE_SHADER_IR_NIR);
   return static_cast<const nir_shader_compiler_options*>(co);
}

static void debug_function(void *private_data,
                   enum nir_spirv_debug_level level, size_t spirv_offset,
                   const char *message)
{
   assert(private_data);
   auto r_log = reinterpret_cast<std::string *>(private_data);
   *r_log += message;
}

struct clover_lower_nir_state {
   std::vector<module::argument> &args;
   uint32_t global_dims;
   nir_variable *offset_vars[3];
};

static bool
clover_lower_nir_filter(const nir_instr *instr, const void *)
{
   return instr->type == nir_instr_type_intrinsic;
}

static nir_ssa_def *
clover_lower_nir_instr(nir_builder *b, nir_instr *instr, void *_state)
{
   clover_lower_nir_state *state = reinterpret_cast<clover_lower_nir_state*>(_state);
   nir_intrinsic_instr *intrinsic = nir_instr_as_intrinsic(instr);

   switch (intrinsic->intrinsic) {
   case nir_intrinsic_load_base_global_invocation_id: {
      nir_ssa_def *loads[3];

      /* create variables if we didn't do so alrady */
      if (!state->offset_vars[0]) {
         /* TODO: fix for 64 bit */
         /* Even though we only place one scalar argument, clover will bind up to
          * three 32 bit values
         */
         unsigned location = state->args.size();
         state->args.emplace_back(module::argument::scalar, 4, 4, 4,
                                  module::argument::zero_ext,
                                  module::argument::grid_offset);

         const glsl_type *type = glsl_uint_type();
         for (uint32_t i = 0; i < 3; i++) {
            state->offset_vars[i] =
               nir_variable_create(b->shader, nir_var_uniform, type,
                                   "global_invocation_id_offsets");
            state->offset_vars[i]->data.location = location + i;
         }
      }

      for (int i = 0; i < 3; i++) {
         nir_variable *var = state->offset_vars[i];
         loads[i] = var ? nir_load_var(b, var) : nir_imm_int(b, 0);
      }

      return nir_u2u(b, nir_vec(b, loads, state->global_dims),
                     nir_dest_bit_size(intrinsic->dest));
   }
   default:
      return NULL;
   }
}

static bool
clover_lower_nir(nir_shader *nir, std::vector<module::argument> &args, uint32_t dims)
{
   clover_lower_nir_state state = { args, dims };
   return nir_shader_lower_instructions(nir,
      clover_lower_nir_filter, clover_lower_nir_instr, &state);
}

static spirv_to_nir_options
create_spirv_options(const device &dev, std::string &r_log)
{
   struct spirv_to_nir_options spirv_options = {};
   spirv_options.environment = NIR_SPIRV_OPENCL;
   if (dev.address_bits() == 32u) {
      spirv_options.shared_addr_format = nir_address_format_32bit_offset;
      spirv_options.global_addr_format = nir_address_format_32bit_global;
      spirv_options.temp_addr_format = nir_address_format_32bit_offset;
      spirv_options.constant_addr_format = nir_address_format_32bit_global;
   } else {
      spirv_options.shared_addr_format = nir_address_format_32bit_offset_as_64bit;
      spirv_options.global_addr_format = nir_address_format_64bit_global;
      spirv_options.temp_addr_format = nir_address_format_32bit_offset_as_64bit;
      spirv_options.constant_addr_format = nir_address_format_64bit_global;
   }
   spirv_options.caps.address = true;
   spirv_options.caps.float64 = true;
   spirv_options.caps.int8 = true;
   spirv_options.caps.int16 = true;
   spirv_options.caps.int64 = true;
   spirv_options.caps.kernel = true;
   spirv_options.caps.int64_atomics = dev.has_int64_atomics();
   spirv_options.debug.func = &debug_function;
   spirv_options.debug.private_data = &r_log;
   return spirv_options;
}

struct disk_cache *clover::nir::create_clc_disk_cache(void)
{
   struct mesa_sha1 ctx;
   unsigned char sha1[20];
   char cache_id[20 * 2 + 1];
   _mesa_sha1_init(&ctx);

   if (!disk_cache_get_function_identifier((void *)clover::nir::create_clc_disk_cache, &ctx))
      return NULL;

   _mesa_sha1_final(&ctx, sha1);

   disk_cache_format_hex_id(cache_id, sha1, 20 * 2);
   return disk_cache_create("clover-clc", cache_id, 0);
}

nir_shader *clover::nir::libclc_spirv_to_nir(const module &mod, const device &dev,
                                             std::string &r_log)
{
   spirv_to_nir_options spirv_options = create_spirv_options(dev, r_log);
   spirv_options.create_library = true;

   auto &section = mod.secs[0];
   const auto *binary =
      reinterpret_cast<const pipe_binary_program_header *>(section.data.data());
   const uint32_t *data = reinterpret_cast<const uint32_t *>(binary->blob);
   const size_t num_words = binary->num_bytes / 4;
   auto *compiler_options = dev_get_nir_compiler_options(dev);
   unsigned char clc_cache_key[20];
   unsigned char sha1[CACHE_KEY_SIZE];
   /* caching ftw. */
   struct mesa_sha1 ctx;

   size_t binary_size = 0;
   uint8_t *buffer = NULL;
   if (dev.clc_cache) {
      _mesa_sha1_init(&ctx);
      _mesa_sha1_update(&ctx, data, num_words * 4);
      _mesa_sha1_final(&ctx, clc_cache_key);

      disk_cache_compute_key(dev.clc_cache, clc_cache_key, 20, sha1);

      buffer = (uint8_t *)disk_cache_get(dev.clc_cache, sha1, &binary_size);
   }

   nir_shader *nir;
   if (!buffer) {
      nir = spirv_to_nir(data, num_words, nullptr, 0,
                                     MESA_SHADER_KERNEL, "clcspirv",
                                     &spirv_options, compiler_options);
      nir_validate_shader(nir, "clover-libclc");
      nir->info.internal = true;
      NIR_PASS_V(nir, nir_lower_variable_initializers, nir_var_function_temp);
      NIR_PASS_V(nir, nir_lower_returns);

      if (dev.clc_cache) {
         struct blob blob = { 0 };
         blob_init(&blob);
         nir_serialize(&blob, nir, true);
         disk_cache_put(dev.clc_cache, sha1, blob.data, blob.size, NULL);
         blob_finish(&blob);
      }
   } else {
      struct blob_reader blob_read;
      blob_reader_init(&blob_read, buffer, binary_size);
      nir = nir_deserialize(NULL, compiler_options, &blob_read);
      free(buffer);
   }

   return nir;
}

module clover::nir::spirv_to_nir(const module &mod, const device &dev,
                                 std::string &r_log)
{
   spirv_to_nir_options spirv_options = create_spirv_options(dev, r_log);
   std::shared_ptr<nir_shader> nir = dev.clc_nir;
   spirv_options.clc_shader = nir.get();

   module m;
   // We only insert one section.
   assert(mod.secs.size() == 1);
   auto &section = mod.secs[0];

   module::resource_id section_id = 0;
   for (const auto &sym : mod.syms) {
      assert(sym.section == 0);

      const auto *binary =
         reinterpret_cast<const pipe_binary_program_header *>(section.data.data());
      const uint32_t *data = reinterpret_cast<const uint32_t *>(binary->blob);
      const size_t num_words = binary->num_bytes / 4;
      const char *name = sym.name.c_str();
      auto *compiler_options = dev_get_nir_compiler_options(dev);

      nir_shader *nir = spirv_to_nir(data, num_words, nullptr, 0,
                                     MESA_SHADER_KERNEL, name,
                                     &spirv_options, compiler_options);
      if (!nir) {
         r_log += "Translation from SPIR-V to NIR for kernel \"" + sym.name +
                  "\" failed.\n";
         throw build_error();
      }

      nir->info.cs.local_size_variable = true;
      nir_validate_shader(nir, "clover");

      // Inline all functions first.
      // according to the comment on nir_inline_functions
      NIR_PASS_V(nir, nir_lower_variable_initializers, nir_var_function_temp);
      NIR_PASS_V(nir, nir_lower_returns);
      NIR_PASS_V(nir, nir_lower_libclc, spirv_options.clc_shader);

      NIR_PASS_V(nir, nir_inline_functions);
      NIR_PASS_V(nir, nir_copy_prop);
      NIR_PASS_V(nir, nir_opt_deref);

      // Pick off the single entrypoint that we want.
      foreach_list_typed_safe(nir_function, func, node, &nir->functions) {
         if (!func->is_entrypoint)
            exec_node_remove(&func->node);
      }
      assert(exec_list_length(&nir->functions) == 1);

      nir_validate_shader(nir, "clover after function inlining");

      NIR_PASS_V(nir, nir_lower_variable_initializers, ~nir_var_function_temp);

      // copy propagate to prepare for lower_explicit_io
      NIR_PASS_V(nir, nir_split_var_copies);
      NIR_PASS_V(nir, nir_opt_copy_prop_vars);
      NIR_PASS_V(nir, nir_lower_var_copies);
      NIR_PASS_V(nir, nir_lower_vars_to_ssa);
      NIR_PASS_V(nir, nir_opt_dce);

      NIR_PASS_V(nir, nir_lower_convert_alu_types, NULL);

      NIR_PASS_V(nir, nir_lower_system_values);
      nir_lower_compute_system_values_options sysval_options = { 0 };
      sysval_options.has_base_global_invocation_id = true;
      NIR_PASS_V(nir, nir_lower_compute_system_values, &sysval_options);

      auto args = sym.args;
      NIR_PASS_V(nir, clover_lower_nir, args, dev.max_block_size().size());

      NIR_PASS_V(nir, nir_lower_mem_constant_vars,
                 glsl_get_cl_type_size_align);
      NIR_PASS_V(nir, nir_lower_vars_to_explicit_types,
                 nir_var_uniform | nir_var_mem_shared |
                 nir_var_mem_global | nir_var_function_temp,
                 glsl_get_cl_type_size_align);

      NIR_PASS_V(nir, nir_lower_memcpy);

      /* use offsets for kernel inputs (uniform) */
      NIR_PASS_V(nir, nir_lower_explicit_io, nir_var_uniform,
                 nir->info.cs.ptr_size == 64 ?
                 nir_address_format_32bit_offset_as_64bit :
                 nir_address_format_32bit_offset);

      NIR_PASS_V(nir, nir_lower_explicit_io, nir_var_mem_constant,
                 spirv_options.constant_addr_format);
      NIR_PASS_V(nir, nir_lower_explicit_io, nir_var_mem_shared,
                 spirv_options.shared_addr_format);

      NIR_PASS_V(nir, nir_lower_explicit_io, nir_var_function_temp,
                 spirv_options.temp_addr_format);

      NIR_PASS_V(nir, nir_lower_explicit_io, nir_var_mem_global,
                 spirv_options.global_addr_format);

      NIR_PASS_V(nir, nir_remove_dead_variables, nir_var_all, NULL);

      if (compiler_options->lower_int64_options)
         NIR_PASS_V(nir, nir_lower_int64);

      NIR_PASS_V(nir, nir_opt_dce);

      struct blob blob;
      blob_init(&blob);
      nir_serialize(&blob, nir, false);

      const pipe_binary_program_header header { uint32_t(blob.size) };
      module::section text { section_id, module::section::text_executable, header.num_bytes, {} };
      text.data.insert(text.data.end(), reinterpret_cast<const char *>(&header),
                       reinterpret_cast<const char *>(&header) + sizeof(header));
      text.data.insert(text.data.end(), blob.data, blob.data + blob.size);

      m.syms.emplace_back(sym.name, section_id, 0, args);
      m.secs.push_back(text);
      section_id++;
   }
   return m;
}
#else
module clover::nir::spirv_to_nir(const module &mod, const device &dev, std::string &r_log)
{
   r_log += "SPIR-V support in clover is not enabled.\n";
   throw error(CL_LINKER_NOT_AVAILABLE);
}
#endif